Fiber-Reinforced Polymers in Freeform Structures: A Review

Abstract

This article is a survey discussing the application of fiber-reinforced polymer composites in freeform structures and their impact on the design and shape generation process. The analysis of case studies showed that the use of FRP composites not only helps to overcome some challenges in the construction of objects with complex geometry, but also creates brand new types of structures and design approaches. On the other hand, there is a problem—although FRP materials are frequently used in construction, the shapes of structures and design methods are often traditional and are simply copied from materials such as wood, concrete, and steel. FRP composites have been applied in civil engineering for several decades, since the 1960s, as building envelopes, façade skins, load-bearing structures, and internal and external reinforcement. The article aims to analyze this accumulated experience and to explore the role of FRP materials in the design of buildings with free, complex, fluid, and organic shapes. A new classification of freeform composite structures is proposed. They are classified in this article according to the methodology applied at the conceptual design stage: structures created by using a geometric approach, a form-finding (equilibrium) approach, or a biomimetic approach. Each approach is described in its own separate section, with a thorough literature and state-of-the-art review.

Environmentally Responsive Materials for Building Envelopes: A Review on Manufacturing and Biomimicry-Based Approaches

“…When using composite materials, material testing, design, and fabrications are all considered together since the composite properties, contrary to other raw materials, depend on the nature of their constituents, the proportion, and the fiber’s orientation, as well as the fabrication process. Composite materials such as fiber-reinforced polymers (FRP), glass-fiber polymers (GRP), some metal composites, and concrete composites play a vital role in developing biomimetic envelopes and structures [ 128 ]. Thus, material design and fabrication must work together to adapt biomimicry-based approaches to responsive envelopes.…”

“…Freeform structures refer to complex geometry buildings and their resisting and non-resisting structural parts [ 128 ]. They are desirable in architecture since their curvature may withstand higher lateral forces, and less material is needed when compared with straight walls [ 28 , 128 , 165 , 166 ]. To produce a freeform structure, in some cases, such as with composite materials, a molding process is usually needed.…”

“…The mold surface plays a key role in the quality produced. Here, contact molding, filament winding, and resin infusion require a one-part mold, while press molding, for instance, requires two-part molds [ 128 ]. Another manufacturing technique compatible with freeform design in architecture is three-dimensional concrete printing, or 3DCP, which achieves better geometric performance when printing in straight lines compared to curved lines.…”

“…Another manufacturing technique compatible with freeform design in architecture is three-dimensional concrete printing, or 3DCP, which achieves better geometric performance when printing in straight lines compared to curved lines. Even if this technique has not been widely exploited to link freeform structures and biomimicry-inspired architecture at the moment of this review, previous works [ 128 , 166 , 167 , 168 ] have shown the ability of this technique while printing curved walls that can be of interest to develop responsive facades.…”

Layered-Fabric Materiality Fibre Reinforced Polymers (L-FMFRP): Hysteretic Behavior in Architectured FRP Material

“…The composite piece is shaped by the mold’s morphology, assuring conformity to the requested designed shape as well as material homogeneity [ 6 ]. While being substantial to applications in fields such as the automotive, security or aeronautics sectors, the dependence on rigid molds can be restrictive in the case of architectural applications [ 7 ]. The typical size-of-element and its one-off nature, together with contemporary architectural practices that promote complex morphologies and high variability, stand in contradiction to the practice and economy of mold-based manufacturing.…”